    :handle-ok ::users
    :processable?
    (fn [ctx]
-     (let [e (process ::new-user ctx [:user/tz :user/pass :user/username :user/email] [hash-password])]
+     (let [e (process ::new-user ctx [:user/tz :user/pass :user/username :user/email] [hash-password (partial validate-tz db)])]
        (if (= e :tictag.resources/unprocessable)
          [false {::not-processable (s/explain-data ::new-user (params ctx))}]
          [true {::user e}])))

(defn hash-password [u]
  (update u :user/pass hashp))

(defn users [{:keys [db jwt]}]
  (resource
   collection-defaults

   :handle-ok ::user
   :processable?
   (fn [ctx]
     (let [e (process ::existing-user ctx [:user/tz] (partial validate-tz db))]
       (if (= e :tictag.resources/unprocessable)
         [false nil]
         [true {::changes e}])))
